Гипергеометрическое распределение
P(2;28;4;5)=C(4;2)*C(28-4;5-2) / C(28;5)=6*2024 / 98280 =506/4095
88^(8)-больше, а 8^(88)-меньше
a n m b ____________________20см mn=13 cм
<span>cos ^- 4 x/2 * (2sin^4 x/2 -1) =2</span>
<span>2sin^4 x/2 -1=2cos^4 x/2</span>
<span>2sin^4 x/2 -2cos^4 x/2 =1</span>
<span>2(sin^2 x/2 +cos^2 x/2)(sin^2 x/2-cos^2 x/2)=1</span>
<span>2(sin^2 x/2-cos^2 x/2)=1</span>
<span>-2cosx=1</span>
<span>cosx=-1/2 x=+-arccos(1/2)+2pik x=+-pi/6+2pik (k=0,1,2,3,4,5,...)</span>